The bright orange fist-like club of the mantis shrimp, a 4-inch-long crustacean found in tropical waters, accelerates underwater faster than a .22-caliber bullet and can smash through mollusk shells and crab exoskeletons, researchers at the University of California, Riverside, said.
Engineering Professor David Kisailus set out to find what enabled the club to withstand 50,000 high-velocity strikes on prey during its lifespan.
The shrimp's club is a highly complex structure, he found, composed of three specialized regions that work together to create a structure tougher than many engineered ceramics.
The surface of the club is similar to human bone and supports the impact when the mantis shrimp strikes prey.
Under the surface, highly organized and rotated layers of chitin fibers dispersed in mineral act as a shock absorber, absorbing energy as stress waves pass through the club.
Finally, oriented chitin fibers wrap around the sides of the club, keeping it intact during high-velocity impacts.
"This club is stiff, yet it's light-weight and tough, making it incredibly impact tolerant and interestingly, shock-resistant," Kisailus said in a UC Riverside release Thursday. "That's the holy grail for materials engineers."
Potential applications in structural materials are widespread because the final product could be lighter weight and more impact-resistant than existing products, he said.
The mantis shrimp's impact so powerful, Kisailus said, that he needs to keep his test subject in a special aquarium in his lab so it doesn't break the glass.